Fluid-operated percussive tool.



BAJYLES. Hum OPERATEDPERGUSSQVE TOOL.

, APPLICATION FILED 1M1. I4, 1914- r k Pmantedhne 1918 I a: SHEETS-SHEET a. (Miami arm:

WITNESSES:

mum/r03 A ITO/WE L. c BAYLES. FLUlD OPERATED PERCUSSIYVE TOOL.

APPLICATION FILED mum, 1914.

Pafented .l une4, 1918.

2 SHEETS-SHEET 2.,

a 1 WITNESSES: I/UVEIIITOH T l, tidllllllhltd l f l allllil lhlil ft] LEWIS C. BAYLES, OF EASTON, PENNSYLVANIA, ASSIGNOR T INGERSOLL-RAND COH- PANY, 0F JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

FLUID-OIPERATED PERGUSSIVE TOOL.

mm m...-

Specificetion of Letters Patent.

llatented June 4:, 1918.

Application filed January 14., 1914. Serial No. 811,986.

To all whom it may concern:

Be it known that 1, Lewis G. Barrens, a

- citizen of the United States, residing at flaston, in the county of Northampton and State of Pennsylvania, have invented a certain new and useful Improvement in Fluid- Operated lercussive Tools, (Case A,) of which the following is a specification.

This invention relates to fluid operated percussive tools wherein the admission of the operatingfluid to the cylinder is controlled by the movement of the piston, and has for its objects the production of a simple and-eflicient tool of this class, and also the provision of controlling means for the exhaust from the cylinder that the operatin; fluid has a longer period of expansion, thus increasing the efficiency and dccrcashu; the power consumption. of the tool.

With these objects in view, I have devised a tool practical embodiments of which are shown in the accompanying drawings in Fig. 5, diagrz'rminatic view sl'lowing modified form.

The tool, as shown, comprises a cylinder 1 which has a forward bore, 2, and a rear -ward bore 3 of smaller diameter joining and 35.

meeting the forward bore 2, and forming a direct continuation thereof. In the cylinder reciynocates a differential piston which has a head i fitting and sliding in the forward portion and a shank 5, fitting and sliding in the rearward portion, there being' a dcpressed port-ion or neck (3 between the head 4 and the shank The cmistiaiction is preferably such, and the stroke of the piston is sufficiently lon as to permit the for.-- ward end of the shank :"i to overrun the point of junction of the forward and rearward bores and extend for a substantial dis tance intothc larger forward bore of the cylinder on the working stroke. Operating fluid is admitted to the rearward end of the forward bore 2 by an inlet passage '2' so that there is constant lluid pressure on the rear face of the piston head 4. From an intermediate point in the bore a passage 8 leads to the forward end of the bore 2. the rear the piston head latthe forward end of its opening of this passage 8 being so placed that fluid is iuhnitted from the rear end of the-bore 2 t the forward end and the front end of the piston head 4 when the piston is near the :lorward end of its stroke. From. a pointnear the forward end of the bore 3 a fluid passage 9 leads to the rear end of the bore 3, the forward end of this passage 9 being so placed as to be connected with the rear end of the bore :2 by the depression 6 inl the piston when the piston is near the rear end of its stroke. From a point in the bore 2, forward of the rear opening of the passage 8 and so placed as to be closed by stroke, an exhaust passage 10 leads to a valve chest 11 in which. reciprocates a spool valve 12, the opening of the exhaust passage ll) being so placed as to beclosed by the head 13 of the spool valve 1.2 when this valve 7! is in its rearward position and opening to atmosphere through the port 1e when the spool valvelZ in its forward position. A. similar exhaust passage 15 for the bore 3 is provided which opens from a point in the cylinder forward of the rear opening of the passage J and is controlled by the head 16 of the spool valve 12. To the ends of the valve chest 11 valve operating passages 17 and 1.8 lead respectively from the forward end of the bore 2 and the rearward end of the bore 3.

In operation, supposing the piston and valve to be in positions shown in Fig. 3, fluid will enter through the port 7 and pass by way of. the passage 8 to the forward end of the cylinder bore 2 and by reason of the fact. that the forward surface of the piston head l is larger than the rearward surface, the piston will be moved rearwardly. Fluid from the bore will lie-exhausted through passage 15 and port 1.4 and the exhaust valve 12 be maintained in position by the pressure exerted on the head 13 through the passage l7. As the exhaust passage 10 is closed by the head 13 of the valvel2. the fluid in the forward end ofbore 2 will operate expansively after the passage 8 has been cut off by the piston head 4. until the piston nears the end of its rein-ward stroke, then the de n'ession (5 will allow fluid to pass from the inlet passage 7 through the passage 9 to the back of the cylinder bore 3. The first effect. of admission of fluid to the back'end of bore 3 will be to drive the valve 12 forward opening the exhaust passage and closing the exhaust passage 15. The fluid pressure on the rear end of the piston shank 5 and the rear face of the piston head at will then drive the iston forward, fluid in front of the piston ex austing through the passage 10. The admission of fluid to the rear end of cylinder bore 3 will be cut ofl shortly after the beginning of the forward stroke of the piston by the closing of thepassage 9 by the shank 5 and the remainder of the forward stroke of the piston will be accomplished by the expansion of the fluid in the bore 3 and the direct pressure of the fluid on the rear face of the piston head 4. When the piston nears the end of its forward stroke fluid will again be admitted through passage 8 to the bore 2 throwing the valve 12 rearwardly and repeating the above described cycle of operations.

The valve 12 increases the efficiency of the tool by lengthening the period of expansion of the fluid operating against the alternately supplied pressure areas.

In Fig. 5 a modified form is shown in which the operating fluid is admitted by a passage 19 to the rear end of the bore 3 and for a short portion of the forward stroke to the rear end of the bore 2 through a passage 20 and the depression 6. Fluid for the forward end of'the cylinder bore 2 is admitted by a passage 21 which leads from an intermediate point of the bore 3 to the forward end of the bore 2. Exhaust passage 10 is the same as in the firstdescribed form but a second exhaust passage 22 leads from the rearward part of the bore 2 being covered by the piston head 4 as it approaches the end of its rearward stroke. In this form a valve operating passage 23 leads from the rear end of the bore 2 to the rear end of the valve chest 11. I I

It'is to be understood ,{Qhat the present showing and description discloses only certain specified modifications of my invention and other forms and modifications are included in the spirit and scope of the invention as ex ressed in the claims.

What claim is:

1. In a fluid operated percussive tool, a cylinder, a piston in said cylinder having two pressure areas for driving it forward and a pressure area for driving it rearward,

fluid passages arranged to admit fluid pressure constantly to one of said forwardly operating pressure areas, and alternately to the other of said forwardly operating pressure area, and to said rearwardly operating pressure area, passages from saidcylinder for alternately exhausting the fluid pressure from said alternately supplied pressure areas, and valve mechanism for controlling said exhaust passages.

2. In a fluid operated percussive tool, a cylinder, a piston in said cylinder havward and a pressure area for driving it rearward, fluid passages arranged to admit fluid pressure constantly to a portion of the cylinder to exert pressure on one of said forwardly operating pressure areas, and alternately to portions of the cylinder to exert pressure on the other of said forwardly operating pressure areas and said rearwardly operating pressure area, passages from said cylinder for alternately exhausting the fluid pressure from 'said alternatelv supplied cylinder portions and a valve for controlling said exhaust passages, said valve havingopposed operating pressure areas in communication with said alternately supplied cylinder portions.

In a fluid operated percussive tool, a cylinder, a piston in said cylinder havin two pressure areas for driving it forwar and a pressure area for driving it rearward cylinder having a forward bore and a rearward bore, a piston having a head in said forward bore and a shank in said rearward bore, a fluid passage for conveying fluid constantly to the rear face of said shank, passages for conveying fluid alternately to the forward end of said forward bore and to the rear end of said forward bore, exhaust passages from the alternately supplied cylinder portions and a valve 1nechanism for controlling said exhaust passages.

5. In a fluid operated percussive tool, a

u a n fluid passages arranged to admit fluid pres' sure constantly to a portion of the cylinder cylinder having a larger forward bore and a smaller rearward bore, a piston having a head in said forward bore and a shank in said rearward bore, a fluid passage for conveying fluid constantly to the rearward end of said smaller bore, fluid passages for alternatcly conveying fluid to the ends of said larger bore, exhaust passages for the ends of said larger bore, and valve mechanism for alternately opening and closing said exhaust passages.

(i. In a fluid operated percussive tool, a. cylinder having a larger forward bore and a smaller rearward bore, a piston having a head in said forward bore and a shank in said rearward bore, a fluid passage for com 30 l 1 l l manual in veyingfluid constantly to the rearward end -f said smaller bore, fluid passages con trolled by said piston for alternately con veying fiuid to the ends of said larger bore, 5 exhaust passages for the ends of said larger bore, and valve mechanism for alternately opening and closing said exhaust passages. 7. In a fluid operated percussive tool, a cylinder having a larger forward bore and 0a smaller rearward bore, a pistonhaving a head in said forward bore and a shank 1n said rearward bore, a fluid passage for fconveying fluid constantly to the rearward end ofsaid smaller bore, fluid passages for ':15 alternate1y conveying fluid to the ends of said larger bore, exhaust passages leading from thesides of the larger bore near the ends thereofand'so placed as to he alter nately closed by said piston at the ends of the stroke, and valve mechanism for alter nately opening and closing said exhaust pas. sages. l

. 8. In a fluid operated percussive tool, a cylinder having a larger forward bore and a smaller rearward bore, a piston having a head in said forward bore and a shank in said, rearward bore, means for conveying fluid constantly to the rear end. of the rear ward bore and alternately to the ends of the forward bore, a valve here, exhaust passages leading-from the side of said larger cylinder bore near'the ends thereof to the side of said valve bore, an exhaust port from said valve bore, a valve'sliding in said bore and I Q having a depression adapted to alternately connect said cylinder exhaust passages and said atmospher c port, and ipassages leading from the ends of the larger cylinder bore ""tothe ends of the valve bore to convey fluid 40 to operate said valve,

9; In a fluid operated percussive tool, a cylinder having a forward bore and a 00111 I ,municatihg rearward bore of smaller diam-- eat, a piston having a head fitting iii said forward bore, a shank fitting said rearward bore and a depression between said head and shank, a fluid inlet passage for constantly admitting fluid pressure to the rear end of the rearward bore, a passage for conveying "Bo -fluid from the forward end of the rearward h ore to the forward end of the forward here at the forward end of the piston stroke, a passage from the rearward end of the rear cylinder bore"to the forward end of said frear cylinder bore, so placed as to be com nected with said rear end of the forward cylinder bore by said piston depression at the rear end of thepiston strokejyexhaust passages for the front and rear ends of said forward cylinderhore and a valve mechanism' for controlling said passages. V 10. In a fluid operated percussive tool, a

' r cylinder having a forward bore and a coin municating rearward bore of smaller dianr llBlS eter, a piston having a head. fittingin said" forward here, shank fitting said rearward bore and a depression between saidheadand shank, a fluid inlet passage for constantly admitting fluid pressure to the rear end of the rearward here, a passage for conveying fluid from the forward end of the rearward bore to the forward end of the forwaid bore at the forward end of the piston stroke, a passage frointhe rearward end of the rear cylinder here, to the forward end of said rear cylinder bore, so placed as to be connected with said. rear end of the forward cylinder bore loy said piston depression at the rear end of the piston stroke, exhaust passages leading from the sides 'of the forward cylinder bore near the front and rear ends, a valve for opening and closing said passages, and passages leading to opposite surfaces of the valve from the front and rear ends of the forward. cylinder here.

11. In a fluid operated percussive tool, a

cylinder, a piston-in said cylinder having.

two pressure areas for driving it forward and a pressure area for driving it rearward, fluid passages arranged to admit fluid pressure constantly to one of said forwardly operating pressure areas, and alternately to the other of said forwardly operating pressure areas, and to said rearwardly operating pressure area, a passe from said cylinder for exhausting an alternately supplied cyl-- and a valwa for controlling 13. In a fluid operated percussive tool, a

cylinder, a piston in said cylinder havin, two pressure areas for driving it for-war and a pressure area for driving it rearward, fluid passages arranged to admit fluid pressure constantly to one of said forwardly oper ating pressure areas, and alternately to the other of said forwardly operating pressure areas, and to said rearwardly operating pressure area, an exhaust passage for the forward end of said cylinder and a valve for controlling said passage.

14-. In a fluid operated percussive tool, a cylinder having a forward bore and a rearward bore, a piston having a head in said forward bore and a shank in said rearward bore, a fluid passage fonconveying fiuid constantly to the rear face of said shank, passages for conveying fluid alternately to the forward end of said forward bore and to the rear end of said forward bore, an ex haust passage for the forward end of said cylinder and a valve for controlling said passage.

15. In a fluid operated percussive tool, a cylinder having a forward bore and a rearward bore of smaller diameter joining and meeting theforward bore and thereby forming a direct continuation of said forward bore, a differential piston in said cylinder having a head reciprocating in the forward bore, and 'a shank reciprocating in the smaller rearward bore, a reduced neck connecting the said shank and head, the rear faces of the head and shank forming pressure areas for driving the piston forward, and the forward surface of the head forming an opposing pressure area for driving the piston rearward, the stroke of the piston being sufliciently long to permit the forward portion of said shank to overrun the point of junction of the forward and rearward bores, and extend for a substantial distance into the largerforward bore of the cylinder on.

the working stroke, fluid passages arranged to admit fluid pressure constantly to a portion of the cylinder to exert pressure on one of said forwardly operating pressure areas, and alternately to portions of the cylinder to exert pressure on the other of said forwardly operating areas and said opposing rearwardly operating pressure area, passages from said cylinder for alternately exhausting fluid pressure from said alternately supplied cylinder portions, and a valve for controlling said exhaust passages, said valve having opposed operating pressure areas in communication with said alternately supplied cylinder portions.

16. In a fluid operated percussive tool, a cylinder having a forward bore and a rearward bore of smaller diameter joining and meeting the forward bore and thereby forming a direct continuation of said forward bore, a differential piston in said cylinder 46 having a head reciprocating in the forward bore, and a shank reciprocating in the smaller rearward bore, a reduced neck con-l; necting the said shank and head, the rear faces of the head and shank formingipressure areas for driving the piston forward, and the forward surface of the head forming an opposing pressure area for driving the piston rearward, the stroke of the piston being sufllciently lougdo permit the for: 66 ward portion of said shank to overrun the point of junction of the forward and rearward bores and extend for a substantial distance into the larger forward bore of the cylinder on the working stroke, fluid aS BO sages arranged to constantly admit uid A pressure directly to a rearward portion of one of the cylinder portions to exert pressure on one of said forwardly operating pressure areas, and alternately admit fluid pressure directly to the rearward portion of the. other cylinder bore and to the forward, portion of the larger bore to exert operating pressure on the other of said forwardly operating pressure areas and said rearwardly "[0 operating pressure area, passages from said cylinder for alternatel exhausting "fluid pressure from said a ternately sup lied cylinder portions and a valve-for contro ling said exhaust passages, said valve having opposed operating pressure areasin communication with said alternately supplied cylinder portions.

In testimony whereof I have hereunto set my hand. A

LEWIS C. BAYLES Witnesses:

'V. M. SLATER,

RUssELL H. WILHELM. 

